AJP - GI Journal of Neurophysiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Gastrointest Liver Physiol 284: G37-G45, 2003. First published September 18, 2002; doi:10.1152/ajpgi.00209.2002
0193-1857/03 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
284/1/G37    most recent
00209.2002v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (11)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bachmann, O.
Right arrow Articles by Seidler, U.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bachmann, O.
Right arrow Articles by Seidler, U.
Vol. 284, Issue 1, G37-G45, January 2003

cAMP-mediated regulation of murine intestinal/pancreatic Na+/HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> cotransporter subtype pNBC1

O. Bachmann1, H. Rossmann1, U. V. Berger2, W. H. Colledge3, R. Ratcliff3, M. J. Evans4, M. Gregor1, and U. Seidler1

1 Department of Internal Medicine, University of Tübingen, D-72076 Tübingen, Germany; 2 In Situ Hybridization Core Facility, Beth Israel Deaconess Medical Center, Boston, MA 02115; 3 Department of Physiology, University of Cambridge, Cambridge CB2 3EG; and 4 Cardiff School of Biosciences, Cardiff CF10 3U5, United Kingdom

Basolateral Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> cotransport is essential for intestinal anion secretion, and indirect evidence suggests that it may be stimulated by a rise of intracellular cAMP. We therefore investigated the expression, activity, and regulation by cAMP of the Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> cotransporter isoforms NBC1 and NBCn1 in isolated murine colonic crypts. Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> transport rates were measured fluorometrically in BCECF-loaded crypts, and mRNA expression levels and localization were determined by semiquantitative PCR and in situ hybridization. Acid-activated Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> cotransport rates were 5.07 ± 0.7 mM/min and increased by 62% after forskolin stimulation. NBC1 mRNA was more abundant in colonic crypts than in surface cells, and crypts expressed far more NBC1 than NBCn1. To investigate whether the cAMP-induced Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> cotransport activation was secondary to secretion-associated changes in HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> or cell volume, we measured potential forskolin-induced changes in intracellular pH and assessed Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> transport activity in CFTR -/- crypts (in which no forskolin-induced cell shrinkage occurs). We found 30% reduced Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> transport rates in CFTR -/- compared with CFTR +/+ crypts but similar Na+-HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> cotransport activation by forskolin. These studies establish the existence of an intracellular HCO<UP><SUB>3</SUB><SUP>−</SUP></UP> concentration- and cell volume-independent activation of colonic NBC by an increase in intracellular cAMP.

bicarbonate secretion; colon; ion transport; chloride secretion; 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein


This article has been cited by other articles:


Home page
 J. Physiol.Home page
A. Cinar, M. Chen, B. Riederer, O. Bachmann, M. Wiemann, M. Manns, O. Kocher, and U. Seidler
NHE3 inhibition by cAMP and Ca2+ is abolished in PDZ-domain protein PDZK1-deficient murine enterocytes
J. Physiol., June 15, 2007; 581(3): 1235 - 1246.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
B. Banizs, P. Komlosi, M. O. Bevensee, E. M. Schwiebert, P. D. Bell, and B. K. Yoder
Altered pHi regulation and Na+/HCO3- transporter activity in choroid plexus of cilia-defective Tg737orpk mutant mouse
Am J Physiol Cell Physiol, April 1, 2007; 292(4): C1409 - C1416.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
O. Bachmann, D. Reichelt, B. Tuo, M. P. Manns, and U. Seidler
Carbachol increases Na+-HCO3- cotransport activity in murine colonic crypts in a M3-, Ca2+/calmodulin-, and PKC-dependent manner
Am J Physiol Gastrointest Liver Physiol, October 1, 2006; 291(4): G650 - G657.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Lung Cell. Mol. Physiol.Home page
S. T. Ballard, L. Trout, J. Garrison, and S. K. Inglis
Ionic mechanism of forskolin-induced liquid secretion by porcine bronchi
Am J Physiol Lung Cell Mol Physiol, January 1, 2006; 290(1): L97 - L104.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
A Schwab, H Rossmann, M Klein, P Dieterich, B Gassner, C Neff, C Stock, and U Seidler
Functional role of Na+-HCO3- cotransport in migration of transformed renal epithelial cells
J. Physiol., October 15, 2005; 568(2): 445 - 458.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
O. Bachmann, B. Riederer, H. Rossmann, S. Groos, P. J. Schultheis, G. E. Shull, M. Gregor, M. P. Manns, and U. Seidler
The Na+/H+ exchanger isoform 2 is the predominant NHE isoform in murine colonic crypts and its lack causes NHE3 upregulation
Am J Physiol Gastrointest Liver Physiol, July 1, 2004; 287(1): G125 - G133.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
L. R. Gawenis, K. T. Boyle, B. A. Palmer, N. M. Walker, and L. L. Clarke
Lateral intercellular space volume as a determinant of CFTR-mediated anion secretion across small intestinal mucosa
Am J Physiol Gastrointest Liver Physiol, June 1, 2004; 286(6): G1015 - G1023.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online